#include "../server.hpp"
#include <regex>
#include <fstream>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#define DEFALT_TIMEOUT 10
std::unordered_map<int,std::string> _statu_msg={
    {100,  "Continue"},
    {101,  "Switching Protocol"},
    {102,  "Processing"},
    {103,  "Early Hints"},
    {200,  "OK"},
    {201,  "Created"},
    {202,  "Accepted"},
    {203,  "Non-Authoritative Information"},
    {204,  "No Content"},
    {205,  "Reset Content"},
    {206,  "Partial Content"},
    {207,  "Multi-Status"},
    {208,  "Already Reported"},
    {226,  "IM Used"},
    {300,  "Multiple Choice"},
    {301,  "Moved Permanently"},
    {302,  "Found"},
    {303,  "See Other"},
    {304,  "Not Modified"},
    {305,  "Use Proxy"},
    {306,  "unused"},
    {307,  "Temporary Redirect"},
    {308,  "Permanent Redirect"},
    {400,  "Bad Request"},
    {401,  "Unauthorized"},
    {402,  "Payment Required"},
    {403,  "Forbidden"},
    {404,  "Not Found"},
    {405,  "Method Not Allowed"},
    {406,  "Not Acceptable"},
    {407,  "Proxy Authentication Required"},
    {408,  "Request Timeout"},
    {409,  "Conflict"},
    {410,  "Gone"},
    {411,  "Length Required"},
    {412,  "Precondition Failed"},
    {413,  "Payload Too Large"},
    {414,  "URI Too Long"},
    {415,  "Unsupported Media Type"},
    {416,  "Range Not Satisfiable"},
    {417,  "Expectation Failed"},
    {418,  "I'm a teapot"},
    {421,  "Misdirected Request"},
    {422,  "Unprocessable Entity"},
    {423,  "Locked"},
    {424,  "Failed Dependency"},
    {425,  "Too Early"},
    {426,  "Upgrade Required"},
    {428,  "Precondition Required"},
    {429,  "Too Many Requests"},
    {431,  "Request Header Fields Too Large"},
    {451,  "Unavailable For Legal Reasons"},
    {501,  "Not Implemented"},
    {502,  "Bad Gateway"},
    {503,  "Service Unavailable"},
    {504,  "Gateway Timeout"},
    {505,  "HTTP Version Not Supported"},
    {506,  "Variant Also Negotiates"},
    {507,  "Insufficient Storage"},
    {508,  "Loop Detected"},
    {510,  "Not Extended"},
    {511,  "Network Authentication Required"}
};
std::unordered_map<std::string,std::string> _mime_msg={
    {".aac",        "audio/aac"},
    {".abw",        "application/x-abiword"},
    {".arc",        "application/x-freearc"},
    {".avi",        "video/x-msvideo"},
    {".azw",        "application/vnd.amazon.ebook"},
    {".bin",        "application/octet-stream"},
    {".bmp",        "image/bmp"},
    {".bz",         "application/x-bzip"},
    {".bz2",        "application/x-bzip2"},
    {".csh",        "application/x-csh"},
    {".css",        "text/css"},
    {".csv",        "text/csv"},
    {".doc",        "application/msword"},
    {".docx",       "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
    {".eot",        "application/vnd.ms-fontobject"},
    {".epub",       "application/epub+zip"},
    {".gif",        "image/gif"},
    {".htm",        "text/html"},
    {".html",       "text/html"},
    {".ico",        "image/vnd.microsoft.icon"},
    {".ics",        "text/calendar"},
    {".jar",        "application/java-archive"},
    {".jpeg",       "image/jpeg"},
    {".jpg",        "image/jpeg"},
    {".js",         "text/javascript"},
    {".json",       "application/json"},
    {".jsonld",     "application/ld+json"},
    {".mid",        "audio/midi"},
    {".midi",       "audio/x-midi"},
    {".mjs",        "text/javascript"},
    {".mp3",        "audio/mpeg"},
    {".mpeg",       "video/mpeg"},
    {".mpkg",       "application/vnd.apple.installer+xml"},
    {".odp",        "application/vnd.oasis.opendocument.presentation"},
    {".ods",        "application/vnd.oasis.opendocument.spreadsheet"},
    {".odt",        "application/vnd.oasis.opendocument.text"},
    {".oga",        "audio/ogg"},
    {".ogv",        "video/ogg"},
    {".ogx",        "application/ogg"},
    {".otf",        "font/otf"},
    {".png",        "image/png"},
    {".pdf",        "application/pdf"},
    {".ppt",        "application/vnd.ms-powerpoint"},
    {".pptx",       "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
    {".rar",        "application/x-rar-compressed"},
    {".rtf",        "application/rtf"},
    {".sh",         "application/x-sh"},
    {".svg",        "image/svg+xml"},
    {".swf",        "application/x-shockwave-flash"},
    {".tar",        "application/x-tar"},
    {".tif",        "image/tiff"},
    {".tiff",       "image/tiff"},
    {".ttf",        "font/ttf"},
    {".txt",        "text/plain"},
    {".vsd",        "application/vnd.visio"},
    {".wav",        "audio/wav"},
    {".weba",       "audio/webm"},
    {".webm",       "video/webm"},
    {".webp",       "image/webp"},
    {".woff",       "font/woff"},
    {".woff2",      "font/woff2"},
    {".xhtml",      "application/xhtml+xml"},
    {".xls",        "application/vnd.ms-excel"},
    {".xlsx",       "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
    {".xml",        "application/xml"},
    {".xul",        "application/vnd.mozilla.xul+xml"},
    {".zip",        "application/zip"},
    {".3gp",        "video/3gpp"},
    {".3g2",        "video/3gpp2"},
    {".7z",         "application/x-7z-compressed"}
};

class Util
{
    public:
        //字符串分割函数
        static size_t Split(const std::string& str,const std::string& sep,std::vector<std::string>* arry){
            size_t idx=0,pos=0;
            while(idx<str.size()){
                pos=str.find(sep,idx);
                if(pos==std::string::npos){
                    arry->push_back(str.substr(idx));
                    return arry->size();
                }
                if(pos==idx){
                    idx+=sep.size();
                    continue;
                }
                arry->push_back(str.substr(idx,pos-idx));
                idx=pos+sep.size();
            }
            return arry->size();
        }
        //读取文件内容
        static bool ReadFile(const std::string& filename,std::string* buf){
            std::ifstream ifs(filename,std::ios::binary);
            if(ifs.is_open()==false){
                ERR_LOG("open %s file failed!",filename.c_str());
                return false;
            }
            size_t fsize=0;
            ifs.seekg(0,ifs.end);
            fsize=ifs.tellg();
            ifs.seekg(0,ifs.beg);
            buf->resize(fsize);
            ifs.read(&(*buf)[0],fsize);
            if(ifs.good()==false){
                ERR_LOG("read %s file failed!",filename.c_str());
                ifs.close();
                return false;
            }
            ifs.close();
            return true;
        }
        //向文件内容写入数据
        static bool WriteFile(const std::string& filename,const std::string& buf){
            std::ofstream ofs(filename,std::ios::binary | std::ios::trunc);
            if(ofs.is_open()==false){
                ERR_LOG("open %s file failed!",filename.c_str());
                return false;
            }
            ofs.write(buf.c_str(),buf.size());
            if(ofs.good()==false){
                ERR_LOG("write %s file failed!",filename.c_str());
                ofs.close();
                return false;
            }
            ofs.close();
            return true;
        }
        //URL编码
        //URL编码，避免URL中资源路径与查询字符中的特殊字符与HTTP请求中特殊字符产生歧义
        //编码格式：将特殊字符的ASCII值，转换为两个16进制字符，前缀%， C++ -> C%2B2B
        //不编码的特殊字符： RFC3986文档规定 . - _ ~ 字母，数字属于绝对不编码字符
        //RFC3986文档规定，编码格式 %HH
        //W3C标准中规定，查询字符串中的空格，需要编码为+，编码则是+转空格
        static std::string UrlEncode(const std::string& url,bool convert_space_to_plus){
            std::string res;
            for(auto &c : url){
                if(c=='-' || c=='_' || c=='.' || c=='~' || isalnum(c)){
                    res+=c;continue;
                }
                if(c==' ' && convert_space_to_plus){
                    res+='+';continue;
                }
                //剩下的字符都是需要编码成为 %HH 格式
                char tmp[4]={0};
                snprintf(tmp,4,"%%%02X",c);
                res+=tmp;
            }
            return res;
        }
        static char HEXTOI(char c){
            if(c>='0'&&c<='9'){
                return c-'0';
            }else if(c>='a'&&c<='z'){
                return c-'a'+10;
            }else if(c>='A'&&c<='Z'){
                return c-'A'+10;
            }
            return -1;
        }
        //URL解码
        static std::string UrlDecode(const std::string& url,bool convert_space_to_plus){
            std::string res;
            for(size_t i=0;i<url.size();i++){
                if(url[i]=='+' && convert_space_to_plus){
                    res+=' ';continue;
                }
                if(url[i]=='%' && (i+2)<url.size()){
                    char v1=HEXTOI(url[i+1]);
                    char v2=HEXTOI(url[i+2]);
                    char v=(v1<<4)+v2;
                    res+=v;
                    i+=2;
                    continue;
                }
                res+=url[i];
            }
            return res;
        }
        //响应状态码的描述信息获取
        static std::string StatuDesc(int statu){
            auto it=_statu_msg.find(statu);
            if(it!=_statu_msg.end()){
                return it->second;
            }
            return "Unknow";
        }
        //根据文件名后缀名获取文件mime
        static std::string ExtMime(const std::string& filename){
            size_t pos=filename.rfind('.');
            if(pos==std::string::npos) return "application/octet-stream";
            std::string str=filename.substr(pos);
            auto it=_mime_msg.find(str);
            if(it!=_mime_msg.end()){
                return it->second;
            }
            return "application/octet-stream";
        }
        //判断一个文件是否是一个目录
        static bool IsDirectory(const std::string& filename){
            struct stat st;
            int ret=stat(filename.c_str(),&st);
            if(ret<0){
                return false;
            }
            return S_ISDIR(st.st_mode);
        }
        //判断一个文件是否是一个普通的文件
        static bool IsRegular(const std::string& filename){
            struct stat st;
            int ret=stat(filename.c_str(),&st);
            if(ret<0){
                return false;
            }
            return S_ISREG(st.st_mode);
        }
        //http请求的资源路径有效性判断
        static bool ValidPath(const std::string& path){
            std::vector<std::string> dirsum;
            int level=0;
            Split(path,"/",&dirsum);
            for(auto& dir : dirsum){
                if(dir==".."){
                    level--;
                    if(level<0) return false;
                    continue;
                }
                level++;
            }
            return true;
        }
};

class HttpRequest
{
    public:
        std::string _method; //请求方法
        std::string _path; //资源路径
        std::string _version; //协议版本
        std::string _body; //请求正文
        std::smatch _matches; // 资源路径的正则提取数据
        std::unordered_map<std::string,std::string> _headers; //头部字段
        std::unordered_map<std::string,std::string> _params; //查询字符串
    public:
        HttpRequest():_version("HTTP/1.1") {}
        void Reset(){
            _method.clear();
            _path.clear();
            _version="HTTP/1.1";
            _body.clear();
            std::smatch match;
            _matches.swap(match);
            _headers.clear();
            _params.clear();
        }
        //插入头部字段
        void SetHeader(const std::string& key,const std::string& val){
            _headers.insert(std::make_pair(key,val));
        }
        //判断是否存在指定头部字段
        bool HasHeader(const std::string& key){
            auto it=_headers.find(key);
            return it==_headers.end()?false:true;
        }
        //获取指定头部字段的值
        std::string GetHeader(const std::string& key){
            if(!HasHeader(key)){
                return "";
            }
            auto it=_headers.find(key);
            return it->second;
        }
        //插入查询字符串
        void SetParam(const std::string& key,const std::string& val){
            _params.insert(std::make_pair(key,val));
        }
        //判断是否有某个指定的查询字符串
        bool HasParam(const std::string& key){
            auto it=_params.find(key);
            return it==_params.end()?false:true;
        }
        //获取指定的查询字符串
        std::string GetParam(const std::string& key){
            if(!HasParam(key)){
                return "";
            }
            auto it=_params.find(key);
            return it->second;
        }
        //获取正文长度
        size_t ContentLength(){
            bool ret=HasHeader("Content-Length");
            if(ret==false){
                return 0;
            }
            std::string slen=GetHeader("Content-Length");
            return std::stol(slen);
        }
        //判断是否是短连接
        bool Close(){
            //DBG_LOG("%d",HasHeader("Connection"));
            //DBG_LOG("%d",GetHeader("Connection")=="keep-alive");
            //DBG_LOG("[%s]",GetHeader("Connection").c_str());
            if(HasHeader("Connection") && GetHeader("Connection")=="keep-alive"){
                return false;
            }
            return true;
        }
};

class HttpResponse
{
    public:
        int _statu;
        bool _redirect_flag;
        std::string _body;
        std::string _redirect_url;
        std::unordered_map<std::string,std::string> _headers;
    public:
        HttpResponse():_statu(200),_redirect_flag(false) {}
        HttpResponse(int statu):_statu(statu),_redirect_flag(false) {}
        void Reset(){
            _statu=200;_redirect_flag=false;_body.clear();_redirect_url.clear();_headers.clear();
        }
        void SetHeader(const std::string& key,const std::string& val){
            _headers.insert(std::make_pair(key,val));
        }
        bool HasHeader(const std::string& key){
            auto it=_headers.find(key);
            return it==_headers.end()?false:true;
        }
        std::string GetHeader(const std::string& key){
            auto it=_headers.find(key);
            if(it!=_headers.end()){
                return it->second;
            }
            return "";
        }
        void SetContent(const std::string& body,const std::string& type="text/html"){
            _body=body;
            SetHeader("Content-Type",type);
        }
        void SetRedirect(const std::string& url,int statu=302){
            _statu=statu;
            _redirect_flag=true;
            _redirect_url=url;
        }
        bool Close(){
            if(HasHeader("Connection") && GetHeader("Connection")=="keep-alive" ){
                return false;
            }
            return true;
        }
};

typedef enum {
    RECV_HTTP_ERROR,
    RECV_HTTP_LINE,
    RECV_HTTP_HEAD,
    RECV_HTTP_BODY,
    RECV_HTTP_OVER
}HttpRecvStatu;


#define MAX_LINE 8192
class HttpContext
{
    private:
        int _resp_statu; //响应状态码
        HttpRecvStatu _recv_statu; //当前接收及解析的阶段状态
        HttpRequest _request; //已经解析得到的请求信息
    private:
        bool RecvHttpLine(Buffer* buf){
            if(_recv_statu!=RECV_HTTP_LINE) return false;
            //获取一行数据
            std::string line = buf->GetLine();
            //考虑一些的要素：缓冲区中的数据不足一行，获取的一行数据超大
            if(line.size()==0){
                //缓冲区的数据不足一行，则需要判断缓冲区的可读数据长度，如果很长了都不足一行，这是有问题 
                if(buf->ReadAbleSize() > MAX_LINE){
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 414; //URI TOO LONG
                    return false;
                }
                //缓冲区数据不足一行，但是也不多，就等等新数据的到来
                return true;
            }
            if(line.size()>MAX_LINE){
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 414; //URI TOO LONG
                return false; 
            }
            bool ret=ParseHttpLine(line);
            if(ret==false){
                return false;
            }
            buf->MoveReadOffset(line.size());
            //首行处理完毕，进入头部获取阶段
            _recv_statu=RECV_HTTP_HEAD;
            return true;
        }
        bool ParseHttpLine(const std::string& line){
            std::smatch matches;
            std::regex e("(GET|HEAD|POST|PUT|DELETE) ([^?]*)(?:\\?(.*))? (HTTP/1\\.[01])(?:\n|\r\n)?",std::regex::icase);
            bool ret=std::regex_match(line,matches,e);
            if(ret==false){
                _recv_statu=RECV_HTTP_ERROR;
                _resp_statu=400;
                return false;
            }
            //请求方法获取
            _request._method=matches[1];
            std::transform(_request._method.begin(),_request._method.end(),_request._method.begin(),::toupper);
            //资源路径的获取，需要进行URL解码操作，但是不需要+转空格
            _request._path=Util::UrlDecode(matches[2],false);
            //协议版本的获取
            _request._version=matches[4];
            //查询字符串的获取与处理
            std::vector<std::string> query_string_arry;
            std::string query_string=matches[3];
            //查询字符串的格式 key=val&key=val... 先以&符合分割，得到各个字串
            Util::Split(query_string,"&",&query_string_arry);
            //针对各个字串，以=符合进行分割，得到key和val，得到之后也需要进行url解码
            for(auto& str : query_string_arry){
                size_t pos=str.find('=');
                if(pos==std::string::npos){
                    _recv_statu=RECV_HTTP_ERROR;
                    _resp_statu=400;
                    return false;
                }
                std::string key=Util::UrlDecode(str.substr(0,pos),true);
                std::string val=Util::UrlDecode(str.substr(pos+1),true);
                _request.SetParam(key,val);
            }
            return true;
        }
        bool RecvHttpHead(Buffer* buf){
            if(_recv_statu!=RECV_HTTP_HEAD) return false;
            //一行一行取出数据，直到遇到空行，头部的格式 key: val\r\nkey: val\r\n...
            while(1){
                std::string line=buf->GetLineAndPop();
                if(line.size()==0){
                    if(buf->ReadAbleSize()>MAX_LINE){
                        _recv_statu=RECV_HTTP_ERROR;
                        _resp_statu=414;
                        return false;
                    }
                    return true;
                }
                if(line.size()>MAX_LINE){
                    _recv_statu=RECV_HTTP_ERROR;
                    _resp_statu=414;
                    return false;
                }
                if(line=="\n" || line=="\r\n"){
                    break;
                }
                bool ret=ParseHttpHead(line);
                if(ret==false){
                    return false;
                }
            }
            //头部处理完毕，进入正文获取阶段
            _recv_statu=RECV_HTTP_BODY;
            return true;
        }
        bool ParseHttpHead(std::string& line){
            //key:val ...
            if(line.back()=='\n') line.pop_back();// 末尾是换行则去掉换行字符
            if(line.back()=='\r') line.pop_back();
            size_t pos=line.find(": ");
            if(pos==std::string::npos){
                _recv_statu=RECV_HTTP_ERROR;
                _resp_statu=400;
                return false;
            }
            std::string key=line.substr(0,pos);
            std::string val=line.substr(pos+2);
            _request.SetHeader(key,val);
            return true;
        }
        bool RecvHttpBody(Buffer *buf){
            if(_recv_statu!=RECV_HTTP_BODY) return false;
            //1 获取正文长度
            size_t content_length=_request.ContentLength();
            if(content_length==0){
                //没有正文，解析完毕
                _recv_statu=RECV_HTTP_OVER;
                return true;
            }
            // 当前已经接收了多少正文，其实就是往 _request._body 中放了多少数据了
            size_t real_len=content_length - _request._body.size();//实际还需要接收的正文长度
            // 接收正文放到body中，但是也要考虑当前缓冲区中的数据，是否全部的正文
            //  缓冲区中数据，包含了当前请求的所有正文，则取出所需的数据
            if(buf->ReadAbleSize() >= real_len){
                _request._body.append(buf->ReadPosition(),real_len);
                buf->MoveReadOffset(real_len);
                _recv_statu=RECV_HTTP_OVER;
                return true;
            }
            _request._body.append(buf->ReadPosition(),buf->ReadAbleSize());
            buf->MoveReadOffset(buf->ReadAbleSize());
            return true;
        }
    public:
        HttpContext():_resp_statu(200),_recv_statu(RECV_HTTP_LINE) {}
        int RespStatu(){
            return _resp_statu;
        }
        HttpRecvStatu RecvStatu(){
            return _recv_statu;
        }
        HttpRequest& Request(){
            return _request;
        }
        void Reset(){
            _resp_statu=200;
            _recv_statu=RECV_HTTP_LINE;
            _request.Reset();
        }
        //接收并解析HTTP请求
        void RecvHttpRequest(Buffer* buf){
            //不同的状态，做不同的事情，但是这里不要break，因为处理完请求行后，应该立即处理头部
            switch(_recv_statu){
                case RECV_HTTP_LINE: RecvHttpLine(buf);
                case RECV_HTTP_HEAD: RecvHttpHead(buf);
                case RECV_HTTP_BODY: RecvHttpBody(buf);
            }
            return;
        }
};


class HttpServer
{
    private:
        using Handler = std::function<void(const HttpRequest&,HttpResponse *)>;
        using Handlers = std::vector<std::pair<std::regex,Handler>>;
        Handlers _get_route;
        Handlers _post_route;
        Handlers _put_route;
        Handlers _delete_route;
        //静态资源跟目录
        std::string _basedir;
        TcpServer _server;
    private:
        void ErrorHandler(const HttpRequest& req,HttpResponse* rsp){
            //组织一个错误展示页面
            std::string body;
            body += "<html>";
            body += "<head>";
            body += "<meta http-equiv='Content-Type' content='text/html;charset=utf-8'>";
            body += "</head>";
            body += "<body>";
            body += "<h1>";
            body += std::to_string(rsp->_statu);
            body += " ";
            body += Util::StatuDesc(rsp->_statu);
            body += "</h1>";
            body += "</body>";
            body += "</html>";
            //将页面数据，当作响应正文，放入rsp中
            rsp->SetContent(body,"text/html");
        }
        //将Http Response中的要素按照http协议格式进行组织，发送
        void WriteReponse(const PtrConnection& conn,HttpRequest& req,HttpResponse& rsp){
            //先完善头部字段
            if(req.Close() == true){
                rsp.SetHeader("Connection","close");
            }else {
                rsp.SetHeader("Connection","keep-alive");
            }
            if(rsp._body.empty() == false && rsp.HasHeader("Content-Length") == false){
                rsp.SetHeader("Content-Length",std::to_string(rsp._body.size()));
            }
            if(rsp._body.empty() == false && rsp.HasHeader("Content-Type") == false){
                rsp.SetHeader("Content-Type","application/octet-stream");
            }
            if(rsp._redirect_flag == true){
                rsp.SetHeader("Location",rsp._redirect_url);
            }
            //将rsp中的要素，按照http协议格式进行组织 
            std::stringstream rsp_str;
            rsp_str << req._version << " " << std::to_string(rsp._statu) << " " << Util::StatuDesc(rsp._statu) << "\r\n";
            for (auto &head : rsp._headers) {
                rsp_str << head.first << ": " << head.second << "\r\n";
            }
            rsp_str << "\r\n";
            rsp_str << rsp._body;
            //发送数据
            conn->Send(rsp_str.str().c_str(), rsp_str.str().size());
        }
        bool IsFileHandler(const HttpRequest& req){
            // 必须设置了静态资源根目录
            if(_basedir.empty()) return false;
            // 请求方法，必须是GET/HEAD请求方法
            if(req._method!="GET" && req._method!="HEAD") return false;
            // 请求的资源路径必须是一个合法路径
            if(Util::ValidPath(req._path)==false) return false;
            // 请求的资源必须存在
            //  有一种请求比较特殊 纯碎的相对根目录：/ ，这种情况给后边默认追加一个 index.html
            //不要忘了前缀的相对根目录，也就是将请求路径转换为实际存在的路径 /image/a.png   ->   ./wwwroot/image/a.png
            std::string req_path= _basedir + req._path;
            if(req._path.back() == '/'){
                req_path+="index.html";
            } 
            if(Util::IsRegular(req_path)==false){
                return false;
            }
            //req._path = req_path;//如果请求就是静态资源请求，则将_path修改为实际的存储路径，以遍于后边静态的文件的处理
            return true;
        }
        //静态资源的请求处理
        bool FileHandler(const HttpRequest& req,HttpResponse* rsp){
            std::string req_path= _basedir + req._path;
            if(req._path.back() == '/'){
                req_path+="index.html";
            } 
            bool ret = Util::ReadFile(req_path,&rsp->_body);
            if(ret==false){
                return false;
            }
            std::string mime=Util::ExtMime(req_path);
            rsp->SetHeader("Content-Type",mime);
            return true;
        }
        //功能性请求的处理
        void Dispatcher(HttpRequest& req,HttpResponse* rsp,Handlers& handlers){
            //在对应请求方法的路由表中，查找是否含有对应资源请求的处理函数，有则调用，没有则发挥404
            //思想：路由表存储的是键值对 -- 正则表达式&处理函数
            //使用正则表达式，对请求的资源路径进行正则匹配，匹配成功就使用对应函数进行处理
            for(auto& handler : handlers){
                const std::regex& re = handler.first;
                const Handler& functor = handler.second;
                bool ret=std::regex_match(req._path,req._matches,re);
                if(ret==false){
                   continue;
                }
                return functor(req,rsp);
            }
            rsp->_statu=404;
        }
        void Route(HttpRequest& req,HttpResponse* rsp){
            //对请求进行分辨，是一个静态资源请求，还是一个功能性请求
            //静态资源请求，则进行静态资源的处理
            //功能性请求，则需要通过几个请求路由表来确定是否有处理函数
            //既不是静态资源请求，也没有设置对应的功能性请求处理函数，就返回404
            if(IsFileHandler(req) == true){
                //是一个静态资源请求，则进行静态资源请求的处理
                FileHandler(req,rsp);
            }
            if(req._method == "GET" || req._method == "HEAD"){
                return Dispatcher(req,rsp,_get_route);
            }else if(req._method == "POST"){
                return Dispatcher(req,rsp,_post_route);
            }else if(req._method == "PUT"){
                return Dispatcher(req,rsp,_put_route);
            }else if(req._method == "DELETE"){
                return Dispatcher(req,rsp,_delete_route);
            }
            rsp->_statu=405;//Method Not Allowed
        }
        //设置上下文
        void OnConnected(const PtrConnection& conn){
            conn->SetContext(HttpContext());
            DBG_LOG("NEW CONNECTION %p", conn.get());
        }
        //缓冲区数据解析+处理
        void OnMessage(const PtrConnection& conn,Buffer* buffer){
            while(buffer->ReadAbleSize() > 0){
                //获取上下文
                HttpContext* context=conn->GetContext()->get<HttpContext>();
                //通过上下文对缓冲区数据进行解析，得到Http Request对象
                //如果缓冲区的数据解析出错，就直接回复出错响应
                context->RecvHttpRequest(buffer);
                HttpRequest& req=context->Request();
                HttpResponse rsp(context->RespStatu());
                if(context->RespStatu() >= 400){
                    //进行出错响应，关闭连接
                    ErrorHandler(req,&rsp);//填充一个错误显示页面数据到rsp中
                    WriteReponse(conn,req,rsp);//组织响应发送给客户端
                    context->Reset();
                    buffer->MoveReadOffset(buffer->ReadAbleSize());
                    conn->Shutdown();//关闭连接
                    return;
                }
                if(context->RecvStatu() != RECV_HTTP_OVER){
                    //当前请求还没有接收完整，则退出，等新数据到来再重新继续处理
                    return;
                }
                //请求路由 + 业务处理
                Route(req,&rsp);
                // 对Http Response进行组织发送
                WriteReponse(conn,req,rsp);
                //重置上下文
                context->Reset();
                // 根据长短连接判断是否关闭连接或者继续处理
                if(rsp.Close()) conn->Shutdown();
            }
        } 
    public:
        HttpServer(int port,int timeout = DEFALT_TIMEOUT)
            :_server(port)
        {
            _server.EnableInactiveRelease(timeout);
            _server.SetConnectedCallback(std::bind(&HttpServer::OnConnected,this,std::placeholders::_1));
            _server.SetMessageCallback(std::bind(&HttpServer::OnMessage,this,std::placeholders::_1,std::placeholders::_2));
        }
        void SetBaseDir(const std::string& path){
            bool ret=Util::IsDirectory(path);
            assert(ret == true);
            _basedir=path;
        }
        void Get(const std::string& pattern, const Handler& handler){
            _get_route.push_back(std::make_pair(std::regex(pattern),handler));
        }
        void Post(const std::string& pattern, const Handler& handler){
            _post_route.push_back(std::make_pair(std::regex(pattern),handler));
        }
        void Put(const std::string& pattern, const Handler& handler){
            _put_route.push_back(std::make_pair(std::regex(pattern),handler));
        }
        void Delete(const std::string& pattern, const Handler& handler){
            _delete_route.push_back(std::make_pair(std::regex(pattern),handler));
        }
        void SetThreadCount(int count){
            _server.SetThreadCount(count);
        }
        void Listen(){
            _server.Start();
        }
};


